Реакция #2710

Уравнение реакции

2,2-dimethyl-6-bromo-thiochroman-4-one

Compound M

2,2-dimethyl-6-bromo-thiochroman-4-one

pTSA

4-bromotoluene

t-BuLi

pentane

→

title compound

2,2-Dimethyl-4(tol-4-yl)-6-bromo-thiochrom-3-ene

Растворители

THF

ethylacetate

dichloromethane

THF

Условия реакции

Обработка

1. 1
   workup.ADDITIONThis mixture was added to a flask
2. 2
   workup.STIRRINGand stirred for 16 hours at ambient temperature
3. 3
   ДругоеThe reaction was quenched
4. 4
   workup.ADDITIONby adding aq. NH4Cl
5. 5
   Экстракцияthe resulting mixture was extracted with ethylacetate
6. 6
   Промывкаwashed with brine
7. 7
   Другоеdried
8. 8
   Другоеthe solvent was removed by evaporation
9. 9
   ДругоеThe product was isolated by chromatography on silica gel
10. 10
    Температураheated to 50° C. for 3 hours
11. 11
    Промывкаwashed with 10% NaHCO3 (5 mL), brine (5 mL)
12. 12
    Сушкаdried with MgSO4
13. 13
    Другоеthe solvent was removed by evaporation

Методика

To a cold (-78° C.) solution of 4-bromotoluene (720 mg, 4.2 mmol) in THF (8 mL) was added t-BuLi in pentane (1.7M, 0.5 mL, 0.85 mmol). The mixture was warmed to ambient temperature over 30 minutes with stirring. This mixture was added to a flask containing 2,2-dimethyl-6-bromo-thiochroman-4-one (Compound M, 140 mg, 0.4 mmol) and THF (2 mL). and stirred for 16 hours at ambient temperature. The reaction was quenched by adding aq. NH4Cl, and the resulting mixture was extracted with ethylacetate, washed with brine, dried and the solvent was removed by evaporation. The product was isolated by chromatography on silica gel. The material was dissolved in dichloromethane (5 mL) and pTSA (5 mg) was added and heated to 50° C. for 3 hours. The misture was diluted with ethylacetate (20 mL), washed with 10% NaHCO3 (5 mL), brine (5 mL), dried with MgSO4 and the solvent was removed by evaporation to afford the title compound as an off.

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